Re: [GIT PULL] Core block IO bits for 2.6.39 - early Oops

[Jens Axboe <jaxboe@fusionio.com>]

On 2011-03-25 15:14, Markus Trippelsdorf wrote:
> On 2011.03.25 at 15:10 +0100, Jens Axboe wrote:
>> On 2011-03-25 14:09, Markus Trippelsdorf wrote:
>>> On 2011.03.25 at 13:44 +0100, Jens Axboe wrote:
>>>> On 2011-03-25 10:57, Markus Trippelsdorf wrote:
>>>>>
>>>>> Reverting it solves all problems here.
>>>>
>>>> Can you try this one?
>>>
>>> This one doesn't help; I still get the same BUG.
>>>
>>> BTW if you're having trouble reproducing this, here is the only non
>>> stock xfs option that I use on the affected partitions:
>>>
>>> noatime,logbsize=262144
>>
>> This?
> 
> No.

Lets expand the scope a bit, this one?

diff --git a/block/blk-core.c b/block/blk-core.c
index 59b5c00..5876c73 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1193,6 +1193,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
 	struct request *rq;
 	bool ret = false;
 
+	preempt_disable();
 	plug = tsk->plug;
 	if (!plug)
 		goto out;
@@ -1215,6 +1216,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
 		}
 	}
 out:
+	preempt_enable();
 	return ret;
 }
 
@@ -1309,6 +1311,7 @@ get_rq:
 		put_cpu();
 	}
 
+	preempt_disable();
 	plug = current->plug;
 	if (plug) {
 		if (!plug->should_sort && !list_empty(&plug->list)) {
@@ -1324,7 +1327,9 @@ get_rq:
 		req->cmd_flags |= REQ_ON_PLUG;
 		list_add_tail(&req->queuelist, &plug->list);
 		drive_stat_acct(req, 1);
+		preempt_enable();
 	} else {
+		preempt_enable();
 		spin_lock_irq(q->queue_lock);
 		add_acct_request(q, req, where);
 		__blk_run_queue(q, false);


-- 
Jens Axboe